Looks like 4.3 may resolve switchgate. The first beta of 4.3 has a setting labeled "Use side switch to" with "Lock rotation" and "Mute" as the two options.

And interestingly, there is a "multitasking gestures" option. Somehow, 4 and 5 finger gestures can be used to switch apps, go back to the home screen, or open the multitasking panel. Rumors are already flying that iPad 2 may go buttonless, like the Android 3.0 tablets shown at CES.

*edit*
Engadget now has a video showing the new gestures. They look pretty reasonable, and should make it even quicker to switch between apps.